I'm not happy with not having restore media and I'm not patient enough to wait for a 3.5 GB download, so I sought another solution.

The new MacBook Air and Mac mini use a build of 10.7 different from the regular installer from the App Store. If the hard drive is replaced or wiped it's necessary to download the installer from Apple's servers using Lion Recovery from either the Restore Partition or using Lion Internet Recovery.

Firewire or Thunderbolt Target Disk Mode (T key at boot) makes creating a copy of the contents of the drive using another machine an easy matter, but what about the Recovery Partition? For that, first enable the DeBug Menu in Disk Utility on your second machine. Once that has been enabled choose the 'Show every partition' option and the Recovery Partition is visible and the contents can be copied.

At this point it's possible to restore the image that originally came with the MB Air, but if it's a new or wiped drive the restore would lack the Recovery Partition. Adding the recovery partition needs to be done at the command line because Disk Utility at the GUI won't permit creating a partition as small as the Recovery Partition, nor will it hide the partition properly.

The process is fairly clear; reduce the size of the main partition, create the Recovery Partition, then because diskutil is a little confused, correct the size, copy the contents of the Recovery Partition and then designate the type of partition.

Detailed instructions (Use 10.7.x for all of this):

Using Thunderbolt Target Disk Mode from MacBook Air to other machine, image Apple install from the MacBook Air drive to the destination.

Enable the Disk Utility DeBug menu using this command:

defaults write com.apple.DiskUtility DUDebugMenuEnabled -bool true

With the DeBug Menu now visible, enable the 'Show every partition' option, then use the Mount menu command to show the Recovery Partition on Desktop, and image it as well.

Next, establish a 650MB partition on HD. It should be this size: 681574400. Use diskutil info to find the Total Size of main partition = X, then subtract 650MB from that size to get the new size of main partition; i.e., X - 681574400 = NewSize.

This command will resize main partition and create the new Recovery Partition:

This worked, but I ended up with a 681574400 byte partition instead of a 650002432 byte.
The hint mentions both numbers, which doesn't make sense. The original recovery partition has a size of 650002432 bytes. After using "X - 650002432" instead of "X - 681574400" I got a partition with the correct size, even without the second "resizeVolume" command.
Also note that "asr" needs to be called by root, so the last command should start with "sudo asr ..."

"Adding the recovery partition needs to be done at the command line because Disk Utility at the GUI won't permit creating a partition as small as the Recovery Partition, nor will it hide the partition properly."

This is not completely true: Disk Utility lets you create small partitions, you just need to type the partition sizes in the text fields (it won't work dragging the division bars in the graphical representation).
That said, it's true that you cannot specify the partition size down to the byte (but this is not so important, it suffices to give a partition slightly bigger, eg. 0.66Gb, and the image restoration will work the same), and you cannot specify the right partition type neither hide it, so it's definitely easier to use diskutil from the command line.

Still reckon the best way is to download the Installer for your model again.
Create a USB flash installer disk from InstallESD.dmg file inside the Install Mac OX bundle.
It is a policy of mine to immediately create a USB recovery stick before you do anything.

Apple should be leaving the Install files after imaging the machines...but they are not PITA !
Also recovery partition cannot be installed on a RAID set and internet recovery fails as well !